Points per game over the last 40 years

[argolio]

According to Wiki about the 2-pt convert:

The two-point conversion rule has been used in college football since 1958[1] and more recently in Canadian amateur football and the Canadian Football League (1975).[2] In overtime situations in college football, the two-point conversion is the mandatory method of scoring after a touchdown beginning with the third overtime.

The American Football League used the two-point conversion during its ten seasons from 1960 to 1969. After the NFL merged with the AFL, the rule did not immediately carry over to the merged league

[argos1873]

2-point rule came from college football. Very few if any rules have went north to south. Again the yard markers on the field are only there because yardage in football makes a difference. But it doesn't matter if a first down takes 10 yards or 12, or 3. Its only because the amount of yards per play, matter. In rugby they make no difference. Most of the way Canadian football is played nowadays is influenced from American rules. Basically anything since the 1920s has been a rule change that made Canadian football more inline with American football. There is some style changes in American play now that may reflect Canadian football, but I'm not sure of any actual rule changes that make the game more "Canadian".